The invention is in the field of processing printed products and relates to a method and an apparatus for winding and unwinding the products in a scale or imbricated formation. With the method and apparatus according to the invention printed products in scale formation are wound into and unwound from printed product rolls which can be easily handled, transported and stored without any risk of damaging said printed products.
According to the prior art printed products and also other flat articles, which are obtained from production or further processing, e.g. from a rotary press and in the form of a series of imbricated products, are wound up to form rolls or reels for intermediate storage or production buffering. This is e.g. carried out in accordance with U.S. Pat. Nos. 5,176,333 and 5,158,242 of the same Applicant by the winding stations, in that the series of products is wound with the aid of a winding band onto a roll or reel core or hub. One end of the winding band is firmly connected to the roll core and said band is wound onto the empty core. For winding purposes an empty core with winding band is placed on a winding station with a winding configuration and the winding band is wound onto an intermediate roll from the said core. The series of printed products is then wound with the winding band onto the core. The winding band keeps the printed products firmly secure in central manner on the roll and normally has a much smaller width than the printed products. Such a printed product roll is then removed from the winding station, transported away and intermediately stored. If the printed products are required again for further processing, the rolls are collected from the storage location, placed on winding stations having an unwinding configuration and are then unwound. During the unwinding the winding band is again unwound on the intermediate roll and when all the printed products have been unwound it is wound back onto the empty core.
Specifically in the case of printed products made from soft paper and having a relatively large number of pages, it has been found that the winding band strongly draws the products centrally against the core and the outer portions and in particular the corners located on the outside of the roll, project without much stability from the roll surface and are damaged or deformed with considerable ease during handling, transportation and storage. This printed product roll disadvantage can be obviated in that such products are wound in a very confined or tight series, i.e. with a very small product spacing and thick roll layers. However, the aforementioned disadvantage is not obviated in the end region of the wound series, where the roll layer becomes successively thinner.
The same problem also occurs when winding double folds, which have a fold on one face of the roll and a bloom or head on the other. At particular risk are the product corners, over the entire outer circumference of the roll, which have at the front on the roll a fold, which is applied more radially to the roll than the rest of the product. Such rolls are e.g. obtained if preliminary products for telephone directories are wound.
The problem of the invention is to provide a method enabling printed products in imbricated formation to be wound and unwound, it being possible to produce rolls with large diameters and the most varied printed products, which also in the outermost layer of the roll and specifically in the vicinity of the end of the wound series are better protected against deformation and damage at the time of handling, transportation and storage. A further problem of the invention is to provide a winding station and a corresponding core set for performing the method.